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| author | Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> | 2012-11-03 21:58:30 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-11-15 20:18:50 +0100 |
| commit | 7f8547648ce9c96016de0c22f8f304431269bd65 (patch) | |
| tree | 221724a93f7cce3fa5be6bd2e0e3621a0f30ef06 /include/i2c | |
| parent | eaa821788d1d0c854e5145e9130da52e1c15d003 (diff) | |
| download | barebox-7f8547648ce9c96016de0c22f8f304431269bd65.tar.gz barebox-7f8547648ce9c96016de0c22f8f304431269bd65.tar.xz | |
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'include/i2c')
| -rw-r--r-- | include/i2c/at24.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/i2c/at24.h b/include/i2c/at24.h new file mode 100644 index 0000000000..1013308459 --- /dev/null +++ b/include/i2c/at24.h @@ -0,0 +1,35 @@ +/* + * at24.h - platform_data for the at24 (generic eeprom) driver + * (C) Copyright 2008 by Pengutronix + * (C) Copyright 2012 by Wolfram Sang + * same license as the driver + */ + +#ifndef _LINUX_AT24_H +#define _LINUX_AT24_H + +#include <linux/types.h> + +/** + * struct at24_platform_data - data to set up at24 (generic eeprom) driver + * @byte_len: size of eeprom in byte + * @page_size: number of byte which can be written in one go + * @flags: tunable options, check AT24_FLAG_* defines + * + * If you set up a custom eeprom type, please double-check the parameters. + * Especially page_size needs extra care, as you risk data loss if your value + * is bigger than what the chip actually supports! + * + */ + +struct at24_platform_data { + u32 byte_len; /* size (sum of all addr) */ + u16 page_size; /* for writes */ + u8 flags; +#define AT24_FLAG_ADDR16 0x80 /* address pointer is 16 bit */ +#define AT24_FLAG_READONLY 0x40 /* sysfs-entry will be read-only */ +#define AT24_FLAG_IRUGO 0x20 /* sysfs-entry will be world-readable */ +#define AT24_FLAG_TAKE8ADDR 0x10 /* take always 8 addresses (24c00) */ +}; + +#endif /* _LINUX_AT24_H */ |